Rollup merge of #82191 - Soveu:dedup, r=nagisa

Vec::dedup_by optimization

Now `Vec::dedup_by` drops items in-place as it goes through them.
From my benchmarks, it is around 10% faster when T is small, with no major regression when otherwise.

I used `ptr::copy` instead of conditional `ptr::copy_nonoverlapping`, because the latter had some weird performance issues on my ryzen laptop (it was 50% slower on it than on intel/sandybridge laptop)
It would be good if someone was able to reproduce these results.

0 files changed, 0 insertions, 0 deletions